Compositions and methods for treating diseases

ABSTRACT

This invention relates to compositions and methods for treatment of vascular conditions. The invention provides arginine polymers and arginine homopolymers for the treatment and/or prevention of glaucoma, pulmonary hypertension, asthma, chronic obstructive pulmonary disease, erectile dysfunction, Raynaud&#39;s syndrome, heparin overdose, vulvodynia, and wound healing. The invention also provides arginine polymers and arginine homopolymers for use in organ perfusate and preservation solutions.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of application Ser. No. 11/736,689filed on Apr. 18, 2007, now U.S. Pat. No. 7,557,087 which is acontinuation of application Ser. No. 11/070,528 filed on Mar. 1, 2005now abandoned which claims priority to U.S. Provisional Application No.60/549,321, filed Mar. 1, 2004 and which is hereby incorporated byreference.

BACKGROUND OF THE INVENTION

Numerous vascular conditions afflict mammals. Such conditions include,but are not limited to, coronary and peripheral arterial diseases,chronic rejection, vasculopathy associated with diabetes, pulmonaryvascular conditions (e.g., pulmonary arterial hypertension and chronicobstructive pulmonary disease), ocular vascular conditions (e.g.,intraocular pressure and glaucoma), sexual dysfunction vascularconditions (e.g., erectile dysfunction and vulvodynia), and dermalvascular conditions (e.g., Raynaud's phenomenon, scleroderma and woundhealing).

A known compound that has a general dilatory effect on the vascularsystem is nitric oxide (NO). See Nathan et al., Cell (1994) 78:915-916.NO plays an essential role in mammalian physiology and is responsiblefor various functions including vascular tone, endothelium dependentreactions, activation of soluble guanylate cyclase, neurotransmission inthe central and peripheral nervous systems, and activated macrophagecytotoxicity. In particular, as the endothelial-derived relaxationfactor (EDRF), NO plays a crucial role in vasodilation throughout thebody and is a known antagonist of endothelin-1, one of the most potentmammalian vasoconstrictors. See Palmer, R. M., et al., Nature (1987)327:524-526. It is believed that NO functions by binding to heme andactivating soluble guanylate cyclase to increase the cellular content ofcGMP and activate cGMP-dependent protein kinases. The latter bothgenerate vasodilatory effects and reduce blood vessel tone. Otherfunctions of NO include the inhibition of platelet adherence andaggregation, and the inhibition of vascular smooth muscle proliferationand leukocyte adherence. Thus, NO is considered an inhibitor ofstenosis, restenosis, vascular inflammation, vascular cellproliferation, thrombosis, atherosclerosis, and arteriosclerosis.

NO is synthesized, at least in part, from L-arginine by a family ofenzymes known as nitric oxide synthases (NOS). It is believed that NOSconverts L-arginine, NADPH, and oxygen into citrulline, NADH, and NO.NOS occur in several isoforms: an endothelial nitric oxide synthase(eNOS), a machrophage or inducible nitric oxide synthase (iNOS), and aneuronal nitric oxide synthase (nNOS). Unlike its name, eNOS has beendetected not only in endothelial cells and blood vessels, but also inepithelium of tissues including, but not limited to, bronchial cells andneurons of the brain, especially in the pyramidal cells of thehippocampus. Furthermore, iNOS has been detected not only in macrophagesbut also in cells such as hepatocytes, chrondrocytes, endothelial cells,and fibroblasts, in particular under conditions of endothelial damage oras part of a response to injury.

The NOS isoforms can also be categorized as either constitutive orinducible. Constitutive NOS (cNOS) include eNOS and nNOS, while iNOS isinducible. cNOS are usually present in a cell, but remain inactive untilintracellular calcium levels increase resulting in enhancedcalcium/calmodulin binding and subsequent activation. Unlike cNOS, iNOSis calcium independent and is not normally present in cells. However,iNOS can be induced by lipopolysaccharides and certain cytokines. It ispostulated that cytokine activity affects gene expression/splicing, mRNAstability, and protein synthesis, resulting in iNOS. It is also expectedthat the induced form of NOS produces a much greater amount of NO thancNOS, and may even result in toxicity when the L-arginine supply islimited. Induction of iNOS can be inhibited by gluococorticoids and somecytokines.

Recent studies suggest that NOS inhibitors may be associated withendothelial vasodilator dysfunction. In particular, asymmetricdimethylarginine (ADMA), and to a lesser extent, N-monomethylarginine(NMA) are associated with endothelial vasodilator dysfunction. Patientswith coronary and peripheral arterial disease and those with renalfailure have greater amounts of plasma ADMA. However, it has been shownthat while exogenous ADMA vasoconstricts vascular rings in vitro, thevasoconstriction effect can be reversed by L-arginine.

Formation of NO by eNOS is thought to play an important role in normalblood pressure regulation, prevention of endothelial dysfunction such ashyperlipodemia, arteriosclerosis, atherosclerosis, thrombosis,restenosis, ischemia, and apoptosis. eNOS is the predominant synthasepresent in brain and endothelium and may be active under basalconditions. Yamada M., J. Cereb. Blood Flow Metab. (2000) April;20(4):709-17. eNOS can be stimulated by increases in intracellularcalcium that occur in response to receptor-mediated agonists or calciumionophores. Studies further suggest that cNOS activity can be regulatedby a negative feedback manner by NO.

Since intracellular levels of L-arginine are normally greater that NOSenzyme, NO syntheses generally do not depend on extracellularsupplementation. See Harrison, D. G., et al. J. Clin. Invest. (1997)100:2153-2157. However, under certain circumstances, local L-arginineconcentrations might become rate limiting. Such circumstances mightinclude local tissue inflammation, elevated plasma or tissue levels ofADMA; inflammation-induced expression of the iNOS; increased expressionof arginase, and presence of iNOS stimulants such as IFN-γ and LPS. SeeGuoyao, et al. Biochem. J. (1998) 366:1-17.

As a free radical gas, NO has an extremely short half-life. See Morriset al., Am. J. Physiol. (1994) 266:E829-E839. Thus, it is desired toincrease the effective amount of NO in a cell, tissue, and/or organ inorder to induce vascular relaxation, dilation, or vascularization, andoxygenation, and other NO mediated biological processes. Previouspublications suggest that NO can be increased by administering to anorganism a NO donor that releases NO, e.g., glyceryl trinitrate,isosorbide 5-mononitrate, isosorbide dinitrate, pentaerythritol,pentaerythritol tetranitrate, etc. One of the greatest limitations inadministering a NO donor is that in vivo administration of suchcompounds can induce severe systemic hypotension. See Heros et al.,Surgical Neurology, (1976) 5:354-362. Others have suggested thatL-arginine monomers can be administered to prevent vasoconstriction andvascular conditions such as atherosclerosis and restenosis. See Cooke etal., U.S. Pat. No. 5,428,070. L-arginine is taken up by cells by way ofthe y+ transporter. This transport mechanism is limited according to theexpression of the transporter and other molecules competing for thetransporter (including ADMA).

Therefore, it is desirable to find new compositions and methods fortreating and/or preventing vascular conditions or to increase the localtissue concentration of NO without causing clinically significantsystemic hypotension.

SUMMARY OF THE INVENTION

The present invention provides methods for treatment and prevention ofvascular conditions or local tissue NO deficiencies by administering atherapeutically effective amount of a NO enhancer. A NO enhancer is anycomposition that increases the metabolic or enzymatic production of NOby NOS. In preferred embodiments, a NO enhancer is any composition thatincreases the metabolic or enzymatic production of NO by cNOS. Morepreferably a NO enhancer is any composition that increases the metabolicor enzymatic production of NO by iNOS. A NO enhancer does not generallycontain, release, or donate a nitric-oxide moiety (e.g., glyceryltrinitrate). Instead, a NO enhancer can be, for example, an argininepolymer or copolymer, or more preferably an arginine homopolymer.

An arginine polymer refers to a composition wherein arginine is a majorcomponent. An arginine polymer or copolymer preferably comprises ofabout 2-500 arginine residues, more preferably 3-400 arginine residues,more preferably 4-300 arginine residues, more preferably 5-200 arginineresidues, more preferably 6-100 arginine residues, more preferably 7-50arginine residues, more preferably 8-40 arginine residues, or morepreferably 9-30 arginine residues. Preferably at least 50% of theresidues of an arginine polymer or copolymer are arginine, morepreferably at least 60% of the residues of an arginine polymer orcopolymer are arginine, more preferably at least 70% of the residues ofan arginine polymer or copolymer are arginine, more preferably at least80% of the residues of an arginine polymer or copolymer are arginine, ormore preferably at least 90% of the residues of an arginine polymer orcopolymer are arginine.

In preferred embodiments, the NO enhancer is an arginine homopolymer,consisting of arginine residues. An arginine homopolymer can consist ofL-arginine residues, D-arginine residues, or a combination of L- andD-arginine residues. Preferably, an arginine homopolymer consists ofL-arginine residues. The compositions herein are preferably formulatedfor local delivery (e.g., by topical applications or by microinjection).Particular vascular conditions that are treatable and/or preventable bythe composition herein include coronary and peripheral arterialdiseases, chronic rejection, vasculopathy associated with diabetes,scleroderma, glaucoma, pulmonary hypertension, chronic obstructivepulmonary disease, wound healing, anal fissures, vulvodynia, erectiledysfunction, Raynaud's phenomenon, and heparin overdose. Thecompositions herein are also useful in perfusate solutions for thepreservation and perfusion of organs either alone or in combination asan additive to standard perfusates.

DETAILED DESCRIPTION OF THE INVENTION I. Compositions

The term “amino acid” or “residue” as used herein includes any one ofthe twenty naturally-occurring amino acids, the D-form of any one of thenaturally-occurring amino acids, non-naturally occurring amino acids,and derivatives, analogs and mimetics thereof. Any amino acid, includingnaturally occurring amino acids, may be purchased commercially orsynthesized by methods known in the art. Examples ofnon-naturally-occurring amino acids include norleucine (“Nle”),norvaline (“Nva”), β-Alanine, L- or D-naphthalanine, ornithine (“Orn”),homoarginine (homoArg) and others well known in the peptide art,including those described in M. Bodanzsky, “Principles of PeptideSynthesis,” 1st and 2nd revised ed., Springer-Verlag, New York, N.Y.,1984 and 1993, and Stewart and Young, “Solid Phase Peptide Synthesis,”2nd ed., Pierce Chemical Co., Rockford, Ill., 1984, both of which areincorporated herein by reference.

Common amino acids may be referred to by their full name, standardsingle-letter notation, or standard three-letter notation for example:A, Ala, alanine; C, Cys, cysteine; D, Asp, aspartic; E, Glu, glutamicacid; F, Phe, phenylalanine; G, Gly, glycine; H, His, histidine; I, Ileisoleucine; K, Lys, lysine; L, Leu, leucine; M, Met, methionine; N, Asn,asparagine; P, Pro, proline; Q, Gln, glutamine; R, Arg, arginine; S,Ser, serine; T, Thr, threonine; V, Val, valine; W, Trp, tryptophan; X,Hyp, hydroxyproline; Y, Tyr, tyrosine. Any and all of the amino acids inthe compositions herein can be naturally occurring, synthetic, andderivatives or mimetics thereof.

The present invention relates to compositions for the treatment ofvascular conditions by increasing the effective amount of NO. Theeffective amount of NO is increased preferably by increasing themetabolic or enzymatic production of NO. Compositions that effectivelyincrease the amount of NO by increasing the metabolic or enzymaticproduction of NO are referred to herein as “NO enhancers.” In preferredembodiments, a NO enhancer is a composition that increases the effectiveamount of NO produced by NOS. More preferably, a NO enhancer is acomposition that increases the effective amount of NO produced by cNOS,especially eNOS. In other preferred embodiments, a NO enhancer is acomposition that increases the effective amount of NO produced by iNOS.If not specified, a NO enhancer is a composition that increases theeffective amount of NO produced by both the constitutive and inducibleforms of NOS. It is further contemplated by the present invention thatthe metabolic or enzymatic production of NO can be increased byincreasing the effective amount of a NO precursor, e.g., L-arginine, ina cell, tissue or organ. Therefore, any composition that enhances theeffective amount of a NO precursor is a NO enhancer. In preferredembodiments, a NO enhancer is comprised of L-arginine linked to adelivery mechanism that increases the rate of L-arginine transportacross a cell membrane. In some preferred embodiments, the NO enhanceris an arginine polymer or an arginine homopolymer as further describedherein.

A NO enhancer of the present invention does not contain a NO moiety thatis donated or released, as described in e.g. U.S. Pat. Nos. 5,873,359,6,156,975, and 6,358,536. Examples of NO enhancers include precursors ofthe NOS metabolic pathway, or more preferably the iNOS metabolicpathway, and substrates or precursors of the above. It is contemplatedby the present invention that NOS generate NO by converting L-arginineinto NO by an enzymatic reaction. It is further contemplated that iNOSgenerates NO by converting L-arginine into NO by an enzymatic reaction,in particular, in response to vascular stress or injury. Thus, inpreferred embodiments, a NO enhancer is any composition that increasesthe effective amount of arginine, or more preferably L-arginine, in acell, tissue or organ. Such compositions include substrates andprecursors in the arginine synthesis pathway (e.g., citrulline orlysine) (Dhanakoti, Am. J. Physiol. (1990) 253:E437-42), as well asarginine polymers, copolymers and homopolymers. The term argininepolymer includes arginine copolymers and arginine homopolymers.

An arginine polymer or copolymer includes an oligomer containingpreferably 2-500 amino acids in length, more preferably 3-400 aminoacids in length, more preferably 4-300 amino acids in length, morepreferably 5-200 amino acids in length, more preferably 6-100 aminoacids in lengths, more preferably 7-50 amino acids in lengths, or morepreferably 8-30 amino acids in length.

Preferably, at least 50%, more preferably at least 60%, more preferablyat least 70%, more preferably at least 80%, more preferably at least 90%of the amino acid residues of an arginine polymer or copolymer arearginine residues.

In preferred embodiments, an arginine polymer or copolymer includes atleast 3 contiguous arginine residues, more preferably at least 4contiguous arginine residues, more preferably at least 5 contiguousarginine residues, more preferably at least 6 contiguous arginineresidues, more preferably at least 7 contiguous arginine residues, morepreferably at least 8 contiguous arginine residues, more preferably atleast 9 contiguous arginine residues, and more preferably at least 10contiguous arginine residues. In some embodiments, an arginine polymeror copolymer includes about 3 to about 100 contiguous arginine residues,more preferably about 6 to about 50 contiguous arginine residues, morepreferably about 7 to about 30 contiguous arginine residues, and morepreferably about 8 to about 20 contiguous arginine residues.

The contiguous arginine residues can be at the C-terminus of thepolypeptide, N-terminus of the polypeptide or in the center of thepolypeptide (e.g., surrounded by non-arginine amino acid residues).Non-arginine residues are preferably amino acids, amino acidderivatives, or amino acid mimetics that do not significantly reduce therate of membrane transport of the polymer into cells, including, forexample, glycine, alanine, cysteine, valine, leucine, isoleucine,methionine, serine, threonine, α-amino-beta-guanidinopropionic acid,α-amino-γ-guanidinobutyric acid, and α-amino-ε-guanidinocaproic acid. Inpreferred embodiments, the arginine polymer does not include lysine andhistidine monomers.

In some embodiments, an arginine polymer can be attached to one or morebackbone. A backbone can be any structure that allows for the attachmentof one or more NO enhancers, arginine polymers, arginine copolymers,and/or arginine homopolymers. The NO enhancers, arginine polymers,copolymer and/or homopolymers can be attached to the backbone covalentlyor non-covalently, directly or by a linker arm. The backbone can becomposed of monomer units that are covalently and/or non-covalentlylinked. Examples of covalent backbones include oligosaccharides,peptides, lipids and other cross-linked monomers. Examples ofnon-covalent backbones include liposomes, micelles, colloids, proteinaggregates, modified cells, and modified viral particles. The backbonecan form any structure, including but not limited to, linear, branched,hyperbranched, dendrimer, block, star, graft, derivatized, liposomes,michelles, and colloids. In preferred embodiments, one or more argininepolymers, copolymers, or homopolymers are attached to a backbone (e.g.,oligosaccharide) by an ester linkage. In other preferred embodiments,the backbone may be a liposome or a micelle that presents on its surfaceone or more arginine polymers, copolymers, or homopolymers.

The length and composition of the polymers and backbones can be designedto control the rate of transport of the polymer into cells, tissues, andorgans. For example, it has been demonstrated that shorter polyarginine(e.g., r7 or R7 (Seq. ID No. 1)) have the ability to translocate acrossvascular cells using a mechanism independent of known amino acidtransport systems. See Uemura, S., et al., Circ. J. (2002) December; 66(12):1155-60; Kown, M H, et al., Transplantation (2001) June 15;71(11):1542-8; U.S. Pat. Nos. 6,495,663 and 6,593,292. Thus, inpreferred embodiments, the length of the arginine polymer or copolymercan vary depending upon its desired rate of translocation. For example,for quick translocation a composition can comprise of for example, 6-30contiguous arginines, more preferably 7-25 contiguous arginines, morepreferably 8-20 contiguous arginines, or more preferably 9-15 contiguousarginines. For a slower translocation, the number of arginine residuesor contiguous arginine residues can be adjusted (e.g., about 10-700contiguous arginine residues, more preferably about 20-600 contiguousarginine residues, more preferably about 30-500 contiguous arginineresidues, more preferably about 40-400 contiguous arginine residues,more preferably 50-300 contiguous arginine residue, more preferably60-200 contiguous arginine residues, and more preferably 70-100contiguous arginine residues).

An arginine polymer can include L-arginines, D-arginines, or acombination of both L and D-arginines. Generally, the term“polyarginine” as used herein refers to a polymeric sequence ofcontiguous arginine residues. The term “poly-L-arginine” refers to apolymeric sequence composed of all L-arginines. The term“poly-D-arginine” refers to a polymeric sequence composed of allD-arginines. The term “poly-L-arginine” may be abbreviated by an uppercase “R” followed by the number of L-arginine in the peptide (e.g., R9(SEQ. ID NO. 2) represents a 9-mer of contiguous L-arginine residues).The term “poly-D-arginine” may be abbreviated by the lower case “r”followed by the number of D-arginines in the peptide (e.g., r9 (SEQ. IDNO. 2) represents a 9-mer of contiguous D-arginine residues). “Ac”indicates a sequence having an acetylated N-terminal residue (e.g.,AcR9), while “b” indicates a sequence having a biotinylated N-terminalresidue (e.g., bR9).

In preferred embodiments, an arginine polymer or copolymer comprise atleast 50% L-arginine residues, more preferably at least 60% L-arginineresidues, more preferably at least 70% L-arginine residues, morepreferably at least 80% L-arginine residues, more preferably at least90% of L-arginine residues, or more preferably all L-arginine residues.

When a polymer comprises of only arginine residues, it can be referredto herein as an “arginine homopolymer.” An arginine homopolymer cancontain a mixture of L-arginine and D-arginine residues, or acombination of L- and D-arginine residues. Preferably at least 50% ofall arginine residues in an arginine homopolymer are L-arginine, morepreferably at least 60% of all arginine residues in an argininehomopolymer are L-arginine, more preferably at least 70% of all arginineresidues in an arginine homopolymer are L-arginine, more preferably atleast 80% of all arginine residues in an arginine homopolymer areL-arginine, more preferably at least 90% of all arginine residues in anarginine homopolymer are L-arginine, and more preferably all arginineresidues in an arginine homopolymer are L-arginine.

Arginine homopolymers are preferably 2-500 amino acids in length, morepreferably 3-400 amino acids in length, more preferably 4-300 aminoacids in length, more preferably 5-200 amino acids in length, morepreferably 6-100 amino acids in lengths, more preferably 7-50 aminoacids in lengths, more preferably 8-40 amino acids in lengths, or morepreferably 9-30 amino acids in length.

In any of the polymers herein, the terminal ends can be either capped oruncapped. Preferably, the terminal ends of the arginine polymers areuncapped, such that the terminal amino and carboxylic acid group arefree. However, capping is appropriate if it does not reduce thetherapeutic affect of the composition (e.g., reduce the level of NOproduction). Examples of N-terminal caps include: N-acetyl, N-methyl,N-dimethyl, N-ethyl, N-diethyl, N-Boc, N-benzyl group, etc. Examples ofC-terminal caps include an amino group of the form NR₂ (e.g., freeamino, alkylamino, or dialkylamino) to form a terminal amide moiety(CONR₂), wherein each R group is separately H, or a linear, cyclic orbranched C₁-C₁₀ alkyl group, preferably C₁-C₅ alkyl, and more preferablyC₁-C₂ alkyl); or an alkyl alcohol of the form OR, to form a carboxylicacid ester (CO₂R), wherein R is linear, cyclic or branched C₁-C₁₀ alkylgroup, preferably C₁-C₅ alkyl, and more preferably C₁-C₂ alkyl, or thelike. Preferably, such N- and C-capping groups contain no more than 20carbon atoms, and preferably no more than 10 carbon atoms.

In some embodiments, a polymer herein has a formula X-Arg_(n)-Y, whereinX is NH₂ or an N-terminal capping group, Y is COO⁻ or a C-terminalcapping group, and n is an integer from 2-500, more preferably from3-400, more preferably from 4-300, more preferably from 5-200, morepreferably from 6-100, more preferably from 7-50, more preferably from8-40, or more preferably from 9-30.

Preferably, the compositions herein, e.g., arginine polymers, haveenhanced translocation abilities. Homopolymers or peptides containing ahigh percentage of cationic amino acid residues have been shown to havea higher ability to cross the plasma membrane of cells. See Mitchell DJ., et al., J. Peptide Res., (2000) 56, 318-325. Various translocationabilities of arginine polymers and other cationic polymers have beendiscussed in D. J. Mitchell, et al., J. Petide. Res., (2000) 56,318-325; Kown, M H, et al., Transplantation, (2001) Jun. 15;71(11):1542-8; Kown, M. et al., J. Thorac. Cardiovasc. Surg., (2001)May; 121(5):971-80; Uemura, S., et al., Circ J., (2002) December;66(12):1155-60; and Uemura, S., et al., Circulation, (2000) 102;2629-2635. In Preferred embodiments, R5-R12, more preferably R6-R11,more preferable R7-R10, and more preferably R8 or R9 are used to treatand/or prevent vascular conditions.

In any of the embodiments herein, the stereochemistry of amino acids canbe altered to control the stability of a polymer. In general, D-isomersare more resistant to endogenous protease and therefore have a longerhalf-life than L-isomers. On the other hand, L-isomers are moresusceptible to protease activity and degrade more readily intoL-arginine monomers. Therefore, a R9 polymer will degrade more readilythan a r9 polymer and, as a NO enhancer, may increase NO levels in acell, tissue, organ, or organism faster. Thus, the compositions hereincan be adjusted for quick release or slow release by altering thestereochemistry of the arginines.

As discussed above, the amino acids and polypeptides herein can benaturally occurring or synthetic. Amino acids and peptides can beproduced using techniques that are well known in the art, includingchemical synthesis techniques and recombinant DNA techniques. Theproduction of peptides using recombinant DNA techniques is described,for example, in U.S. Pat. No. 5,593,866. Chemical synthesis of peptidescan be accomplished using techniques that are well known in the art,such as TBOC or FMOC protection of alpha-amino groups. See Coligan, etal., Current Protocols in Immunology, (Wiley Interscience Unit 9, 1991).Peptides of the invention can also be synthesized by the well-knownsolid phase peptide synthesis methods. See Merrifield, J. Am. Chem.Soc., (1962) 85:2149; Stewart and Young, Solid Phase Peptide Synthesis(Freeman, San Francisco, 1969) pp. 27-62. These and all other referencesand publication described in this application are incorporated herein byreference for all purposes.

Non-peptide compounds that mimic the function of peptides herein canalso be employed in conjunction with this invention. Such peptidemimetics can be produced as described, for example, by Saragovi et al.,Science (1991) 253:792-95. Peptide mimetics are molecules which mimicelements of protein secondary structure. See, e.g., Pezzuto et al.,Eds., (Chapman and Hall, New York 1993). The underlying rationale behindthe use of peptide mimetics is that the peptide backbone of proteinsexists chiefly to orient amino acid side chains in such a way as tofacilitate molecular interactions. For the purposes of the presentinvention, appropriate peptide mimetics are considered to be theequivalent of the peptides herein.

II. Indications for Use

The compositions herein can be used for treatment and/or prevention ofall vascular conditions afflicting mammals. Common vascular conditionsafflicting mammals include but are not limited to, acute thromboticocclusion, aneurysm, aortoiliac and lower occlusive arterial disease,arterial occlusion, arteriosclerosis atherosclerosis, brachiocephalicand upper extremity occlusive disease, Behcet's Syndrome, carotid arterydisease, chronic rejection, vasculopathy associated with diabetes,clogged arteries, degos, dementia, early embolic stroke, headaches,hemorrhoids, heparin overdose, hereditary angioedema, intracoronarythrombus, intimal hyperplasia, ischemia, lymphedema, myoamoya,myocardial infraction, myointimal hyperplasia, peripheral arterialdisease (PAD), pseudoxanthoma elasticum, restenosis sclerosis,scleroderma, stenosis thoracic outlet syndrome, thromboangiitisobliterans, thrombosis, varicose veins, vasculitis, and venous andlymphatic disease.

In one example, the compositions herein can be administered for thetreatment of heparin overdose. In general, heparin inhibits bloodclotting and the formation of fibrin clots both in vitro and in vivo.Heparin acts at multiple sites in the vascular system. Small amounts ofheparin sodium in combination with antithrombin III (heparin cofactor)can inhibit thrombosis by inactivating activated Factor X and inhibitingthe conversion of prothrombin to thrombin. Once active thrombosis hasdeveloped, larger amounts of heparin sodium can inhibit furthercoagulation by inactivating thrombin and preventing the conversion offibrinogen to fibrin. Heparin sodium can also prevent the formation of astable fibrin clot by inhibiting the activation of the fibrinstabilizing factor.

Currently, compounds available for the treatment of heparin overdoseinclude protamine sulfate. See U.S. Pat. No. 5,919,761 (incorporatedherein by reference for all purposes) (disclosing a prevalent salmineprotamine peptide having 32 amino acid residues with 67% of the totalsequence being arginine and having an arginine 6-mer). Protaminesulfate, however, has numerous negative side effects including,hypotension, bradycardia, pulmonary artery hypotension, depressed oxygenconsumption, thrombocytopenia with pulmonary platelet sequestration, andleukopenia.

The present invention contemplates the use of NO enhancers, or morepreferably arginine polymers, or more preferably arginine homopolymers,to neutralize heparin in treating heparin overdose. In particular,arginine polymers comprising of 70% or more arginine residues arecontemplated. In preferred embodiments at least 7, or more preferably atleast 8, or more preferably at least 9 contiguous arginine residues areincluded in the arginine polymer. It is also preferred that thecontiguous arginine residues be L-arginine.

In some embodiments, arginine homopolymers are used for the treatment ofheparin overdose. The arginine homopolymers are preferably 8-40 aminoacids in length or more preferable 9-30 amino acids in length. NOenhancers used for the treatment of heparin overdose are preferablyformulated for oral or intravenous administration. The NO enhancers maybe administered independently or co-administered with additionaltherapeutic agents such as natural protamine sulfate.

In another example, the present invention contemplates the use of NOenhancers, more preferably arginine polymers, or more preferablyarginine homopolymers, for organ transport and perfusate solutions. Suchsolutions can be used, for example, for organ storage and delivery andfor organ flushing (e.g., quick wash of organs that does not requirestorage). Perfusate solutions that are used for quick organ flushing canpreserve organ function, maintain cellular function, and decreasechronic rejection.

Currently, the largest single unresolved problem in organtransplantation and organ reperfusion is failure of the blood vessels.Endothelial cells form the vascular lining and are sensitive to changesin environmental conditions. When an organ is harvested cellulardeterioration begins immediately and eventually damages the organ.Preservation solutions can extend the period of time that an organremains viable for transplant after it is removed from a donor. Thatperiod may vary between different organs depending on differentlimitations in each organ. For example, with today's technology, heartsand lungs can be preserved safely for about 4-6 hours; livers can bepreserved for about 12-18 hours; and kidneys can be preserved for about24 hours. Preservative solutions can also be used to decrease thelikelihood that a patient receiving an organ will experiencepost-operative vascular conditions, including but not limited to,atherosclerosis, restenosis, transplant arteriosclerosis, stenosis, andischemia.

Numerous preservative solutions have been developed and used to preservemajor organs while they are in cold storage prior to theirtransplantation. A preservative solution or perfusate solution containsa variety of compounds that act as osmotic agents to prevent cellswelling thereby protecting organs from swelling associated cellularnecrosis during storage. The invention herein contemplates the use of NOenhancers, more preferably arginine polymers, and more preferablyarginine homopolymers in preservative solutions and/or perfusatesolutions. The preservative solutions contemplated by the presentinvention include all those known in the art.

For example, two widely used preservative flush solutions which arecommercially available are the Collins (Collins G. M., The Lancet,(1969) 1219-1222) and the Euro-Collins (Squifflet, J. P., et al.,Transplant. Proc., (1981) 13:693-696) solutions. These solutionsresemble intracellular fluid and contain glucose as an osmotic agent.However, despite their widespread use, the Collins and Euro-Collinspreservative solutions do not provide adequate preservation for storagetime greater than about 48 hours.

Higher osmolality preservative solutions have been prepared using, forexample, raffinose and lactobionate in the University of Wisconsinsolution (“UW solution”) (Ploeg R. J., et al, Transplant. Proc., (1988)20 (suppl. 1) 1:935-938); mannitol in the Sacks solution (Sacks S. A.,The Lancet, (1973) 1:1024-1028), sucrose in the phosphate bufferedsucrose (PBS) preservative solution (Lam, F. T., et al, Transplantation,(1989) 47:767-771) and the histidine buffered HTK solution ofBretschneider (Kallerhoff, N. M., et al, Transplantation, (1985)39:485-489). Hypertonic citrate preservative solutions are also known(H. Ross et al, Transplantation, (1976) 21:498-501). However, thesesolutions are unable to extend the preservation of organs beyond about72 hours using cold storage methods.

The UW solution, which is described in more detail in U.S. Pat. Nos.4,879,283 and 4,798,824, incorporated herein by reference for allpurposes, includes roughly 5% by weight hydroxyethyl starch withmolecular weight ranging between 150,000-350,000 Daltons and anosmolality level of about 320 mOsm/liter. Other agents in the UWsolution include, optionally, lactobionate salt, raffinose,electrolytes, glutathione, potassium phosphate, magnesium gluconate,adenosine, insulin, bactrim, dexamethasone, allopurinaol and otheranti-inflammatory, antibiotic, anti-metabolic, and anti-neoplasticagents. Any of the above compounds may be used in a preservationsolution to prevent cell swelling or leakage which can damage the storedorgan. However, the UW solution contains relatively minor bufferingcapacity such that during initial flushing the high pressure may inducevasoconstriction and endothelial damage, because of its high potassiumcontent and high viscosity. See Mohara J., J. Heart Lung Transplant.,(2002) March; 21(3):383-90.

The Bretschneider HTK solution is substantially less viscous than the UWsolution, has higher concentrations of histidine, tryptophane, andagr-ketoglutarate, and contains less potassium. Furthermore, the HTKsolution, unlike the UW solution, does not need to be stored in coldtemperature and requires no additional products prior to use.

Other known preservation solutions include those disclosed in U.S. Pat.Nos. 4,873,230; 6,492,103; and 6,544,726, as well as U.S. ApplicationSerial Nos. 2002/0051779; 2002/0090369; 2002/0132220; and 2003/0118980,all of which are incorporated herein by reference for all purposes.

Thus, it is contemplated by the present invention that a solutioncomprising a therapeutically effective amount of a NO enhancer can beused as an organ transport or perfusate solution. In preferredembodiments, the NO enhancer is an arginine polymer, and more preferablyan arginine homopolymer. The NO enhancer(s) can be formulated as asolution or as a powder that easily dissolves into a solution.

The perfusate solutions of the present invention may optionally include1-10% by weight hydroxyethyl starch. The perfusates of the presentinvention may have a molecular weight ranging between 50,000-700,000Daltons, more preferably 150,000-600,000 Daltons, more preferably250,000-500,000 Daltons, or more preferably 350,000-400,000 Daltons.Preferably, the perfusates herein have an osmolality level rangingbetween 50,000-700,000 mOsm/liter, more preferably 150,000-600,000mOsm/liter, more preferably 250,000-500,000 mOsm/liter, or morepreferably 350,000-400,000 mOsm/liter.

The NO enhancer preservation solutions can optionally comprise one ormore additional agents. Such agents can, for example, modulateosmolality, reduce post-operative restenosis or atherosclerosis, orreduce cell atrophy after harvesting but before transplant. Examples ofadditional agents include, but are not limited to, hyroxyethyl starch,lactobionic acid, gluconate, sodium gluconate, magnesium gluconate,dextran, sucrose, hypoxanthine, a glucocorticoid, a non-glucocorticoidlazaroid, tetracycline, pentoxyphyline, calcium chloride, penicillin,insulin, dexamethasone, glutathione, glucose, potassium phosphate,phosphate, adenosisne, allopurinol, dbcyclic AMP, trehalose,nitroglycerin or any other agents known in the art of preparation forpreservation solutions.

The perfusate solutions herein may be administered to an organ beforeharvesting, during transport, or after transplant. Thus the transportedperfusate solutions may be applied both in vivo and ex vivo to organsbeing transplanted.

The invention herein also contemplates the use of NO enhancer(s) for thetreatment of chronic rejection, vasculopathy, or other complicationsassociated with type-1 diabetes. Type-1 diabetes, also known asinsulin-dependent diabetes mellitus or juvenile diabetes, occurs whenthe immune system fights against the body's own insulin-producing isletcells in the pancreas leading to the eventual destruction of such cells.Without the islet cells, the pancreas produces little or no insulin.Type-1 diabetes accounts for 5-10% of all diabetes cases in the UnitesStates and often results in vascular complications and/or nerve damagethat can affect any organ in the body, including, but not limited to theeyes, kidneys, and heart.

Vascular complications associated with type-1 diabetes include stenosis,angiopathy, high blood pressure, heart attacks, strokes, heart failure,hypertension, and kidney damage. It is thought that type-1 diabetes mayaccelerate the progression of atherosclerosis (hardening of thearteries), which can further lead to coronary artery disease, heartattacks, and strokes. In fact, heart attacks and strokes account forabout 60% and 25% of all deaths in diabetics, respectively. Inparticular, microangiopathy occurs in many diabetics. Microangiopathyrefers to the thickening of the walls of small blood vessels. Angiopathycan cause small blood vessels to bleed, leak protein, and slow the flowof blood through the body. When cells downstream from an angiopathicsite (e.g., ocular cells) do not receive enough blood, they becomedamaged.

Nerve damage, or neuropathy, associated with type-1 diabetes also causesmajor complications that can affect the entire body. For example, nervesthat connect the spinal cord, muscles, skin, blood vessels, and otherorgans may become damaged due to diabetes. Particularly severe is nervedamage affecting the heart. Other vascular and neurological conditionsthat affect diabetics include foot problem and foot pain that developsfrom complications in blood vessels and in the peripheral nervoussystem. Such complications may result in changes to both bone structureand soft tissue structure in the feet of diabetics. It may also causefoot ulcers that are difficult to cure. Overall changes in bonestructure can also lead to increase osteoporosis.

Type 1 diabetes is also the leading cause of new cases of blindness inadults, accounting for approximately 12,000 to 24,000 new cases ofblindness annually. Blindness is usually the result of retinopathy.Other eye disorders that affect diabetics and which may result inblindness include cataracts and glaucoma. Diabetics also face a greaterrisk of suffering from complications associated with influenza orpneumonia causing pulmonary hypertension and other pulmonary vascularconditions. It is also estimated that diabetics are twice as likely tosuffer from depression as non-diabetics.

Thus, the present invention contemplates the use of NO enhancers, morepreferably arginine polymers, or more preferably arginine homopolymers,for the treatment of vasculopathy and/or other complications associatedwith type-1 diabetes. Such conditions include, but are not limited to,glaucoma, foot ulcers, angina, myocardial infraction, and post ischemia.The NO enhancer(s) are preferably delivered locally to a site ofstenosis or microangiopathy (e.g., in kidney arteries, coronaryarteries, foot ulcers, etc.). Delivery may be made by catheter (e.g., aDispatch™ catheter), microinjection, or other localized delivery system.The compositions are formulated according to the route of administrationand may include additional therapeutic agents.

The present invention also contemplates the use of NO enhancers for thetreatment and prevention of vascular conditions associated with veingrafting, e.g., graft coronary artery disease and graft peripheralartery disease. The terms “graft,” “vessel,” “conduit,” and “segment”are used interchangeably herein to refer to any full-length or partialsegment of a conduit, whether naturally occurring or synthetic that thatmay be grafted to bypass an obstruction in the vascular system or toincrease blood flow to a particular region in the vascular system.Exemplary uses of vein grafting include: coronary artery bypass grafting(CABG), peripheral artery bypass grafting (PABG), and venous-arterialgrafting (VAG).

Currently, CABG is the most commonly performed “open heart” operation inthe United States. CABG is a procedure performed to bypass blockage(s)or obstruction(s) of the coronary arteries. The coronary arteries arethe blood vessels that supply blood and fuel to the heart. Ischemiarefers to a condition where the heart does not get enough fuel, such aswhen the coronary artery is blocked or occluded. Ischemia can causemuscle atrophy leading to heart attacks.

When there is blockage in the artery, an individual may experience chestpain. Traditional CABG techniques to treat coronary artery blockageinvolved grafting a portion of the saphenous vein from the leg into theheart to carry blood around the obstruction. At one end the saphenousvein was attached to the aorta, and at the other end the saphenous veinwas attached to the coronary artery beyond the blockage. Recently,surgeons discovered that an artery from the inside of the chest wall(the internal thoracic artery or internal mammary artery) could also beused as a vein graft for CABG. Other arteries and veins may also be usedfor CABG, including, for example, the gastroepiploic artery.

In performing a CABG procedure, it is preferable that the implanted veinor artery segment be autologous, or from the same individual. However,venous and arterial segments from other human donors can also be used.Such segments are referred to herein as allograft segments. Segments mayalso be obtains from other animals, e.g., pigs, and are referred toherein as xenografts. In addition, a vessel conduit provided for a CABGprocedure may be an artificial vessel made from a physiologicallycompatible material, e.g., “DACRON”™, PTFE, or other non-tissue graftmaterial. An artificial vessel is preferably prepared or derivatized,e.g., by carboxylation, sulfonation, or phosphorylation, to containnegatively charged groups for adsorbing or attaching the compositionsherein (e.g., positively charged arginine polymers). The artificialvessel segments can also be designed to be partially porous and toprovide a reservoir region from which the compositions herein cangradually diffuse after it is grafted into a patient. While intimalhyperplasia, inflammation, restenosis or other vascular conditionscannot occur in artificial vessel segments, the invention hereincontemplates the therapeutic effects that the composition can have onthe anastomotic junctions where the artificial segments join thesubject's vascular system. As used herein, the term “isolated” whenreferring to a graft or a conduit refers to that graft or conduit, as itexists outside the patient's body. For grafting, the vessel conduit maybe of any suitable length. For example, a graft can be 1-20 inches long,more preferably 2-15 inches long, more preferably 3-10 inches long, ormore preferably 4-8 inches long.

Thus, the present invention contemplates the application of NOenhancers, more preferable arginine polymers, or more preferablyarginine homopolymers to isolated conduits ex vivo. It also contemplatesthe application of any of the above compositions in vivo to the conduitprior to, during, or post grafting. For example, a saphenous vein or aninternal mammary artery can be contacted in situ prior to ablation withone or more of the compositions herein. After contact with thecompositions, a segment of the vein is removed and grafted onto theheart. In another embodiment, a vein graft is contacted with thecompositions herein ex vivo prior to grafting onto the heart.

It is preferable that the compositions herein be dissolved in sterile,physiologically suitable liquid that minimizes disruption of thephysical and biological function of the vessel conduit. Exemplaryliquids include serum-free culture media, (e.g., DMEM), aqueous salineNaCl solutions (e.g., 0.5-2.0% (w/v) saline or more preferably 0.7-1.0%(w/v) saline), any perfusion or organ preservation solution known in theart or disclosed herein, or any other sterile liquid medium or solutionthat is used in vessel grafting procedures.

Dosages and/or concentrations of a NO enhancers applied to a graft ortarget vein or artery may vary depending on, for example, the size ofthe graft and the NO enhancer used. Preferably, the graft is contactedwith a solution comprising approximately between 0.001 μM-100 mM of a NOenhancer(s), more preferably from 0.01 μM-10 mM of a NO enhancer(s),more preferably from 0.1 μM-1 mM of a NO enhancer(s), and morepreferably from 1 μM-500 μM of a NO enhancer(s), although concentrationabove or below these ranges may also be used. In some embodiments, agraft is contacted with 0.001 mg-10 g of a NO enhancer(s), morepreferably 0.01 mg-5 g of a NO enhancer(s), more preferably 0.1 mg-1 gof a NO enhancer(s), or more preferably 1 mg-500 mg of a NO enhancer(s).

Generally, the conduit is contacted with the NO enhancer, morepreferably arginine polymer, or more preferable arginine homopolymer fora time sufficient to allow for the NO enhancer to be translocated intothe cells of the graft and reduce intimial hyperplasia, atherosclerosis,stenosis, or other vascular conditions occurring post-grafting. Forexample, the vessel is contacted with the compositions herein for about0.1-24 hours, or more preferably 1-240 minutes, more preferably 10-60minutes, or more preferably for a period of time less than 30 minutes.The conduit may be immersed in the solution, ex vivo, so that thecompositions herein penetrate both the interior and exterior walls ofthe vessel. In the alternative, the compositions herein can be appliedto the interior surface of the vessel and the vessel may be clamped orligated at both ends such that only the intraluminal surface of thevessel is in contact with the compositions. In embodiments wherein thecompositions are formulated as perfusate or preservation solutions, thevessels can be contacted with the compositions for longer periods oftime (e.g., days). If the compositions herein are not formulated asperfusate or preservation solutions then lesser contact time ispreferable. Generally, the contacting step can be performed at anyappropriate temperature, but preferably at a temperature ranging from 0°C. to 40° C., more preferably 2° C. to 30° C., or more preferably 4° C.to 20° C.

The site where the vessel conduit is to be grafted can be prepared byconventional methods. Damaged or necrotic tissue is removed and the siteis surgically prepared for attachment of the new vessel conduit,preferably during the time that the vessel conduit is being contactedwith the compositions herein. Following the graft procedure, a patientmay be monitored to verify physiological acceptance of the graft and toassess the levels of blood flow through the grafted vessel over time. Itmay appropriate to administer additional NO enhancer(s) to the conduit,the junctions of the conduit and the patient's vessels, or simply thepatient's vessels surrounding the transplanted conduit after thetransplant. Such compositions may be administered locally, e.g. bymicroinjection.

In a similar manner, the compositions herein can be used to treatvascular conditions associated with the formation of an arteriovenous(AV) shunt. An AV shunt is formed by connecting an artery to a vein. AVshunts are frequently used for hemodialysis, especially for kidneyfailure. Generally, there are two types of shunts: a “natural shunt”that connects an artery to a vein directly, and an “AV graft” (alsoreferred to as an “AV shunt”) that uses a small conduit or vessel toconnect the artery to the vein. A surgical operation is necessary toform an AV shunt. In patients requiring kidney hemodialysis, a dialysismachine may be connected to the AV shunt. AV-shunt surgical proceduresare extremely common procedures in the United States.

However, AV shunts often fail due to a flow limiting stenosis at thevenous anastomosis caused by venous anastomotic intimal hyperplasia(VAIH). It is postulated that VAIH may be the result of repeatedexposure to high pressure from the dialysis machine or the unopposedarterial pressure when not attached to the dialysis machine, which canlead to hyperplasia and stenosis within the vein. See Himmelfarb J.,Curr. Opin. Nephrol. Hypertens. (1999) 8(5):569-72; Woods et al.,Nephrol. Dial. Transplant. (1997) 12(4):657-9. Thus, the presentinvention contemplates the application of NO enhancers, more preferablyarginine polymers, or more preferably arginine homopolymers to the AVgraft, the venous anastomosis, and/or the arterial anastomosis, toprevent VAIH or other vascular conditions associated with the formationof the AV shunt.

In typical embodiments, an AV shunt is contacted with one or more of thecompositions herein prior to, during, or post grafting. For example, thegraft can be immersed in a solution containing one or more NO enhancers.Alternatively, the graft can be infused intraluminally with one or moreNO enhancer and one or both ends of the graft can then be clamped orligated such that only the intraluminal walls of the vessel arecontacted.

The AV graft can be an autograft, allograft, or xenografts. The AV graftcan vary in length as required. Preferably, an AV graft is about 1-15inches long, more preferably about 2-10 inches long, and more preferablyabout 3-5 inches long. The NO enhancers herein can be formulated as asolution that can be applied directly to the graft. Such a solution canhave a concentration ranging from 0.001 μM-100 mM, more preferably from0.01 μM-10 mM, more preferably from 0.1 μM-1 mM, and more preferablyfrom 1 μM-500 μM of a NO enhancer herein, although concentration aboveor below these ranges can also be used. In other embodiments, a graft iscontacted with 0.001 mg to 10 g of a NO enhancer, more preferably 0.01mg to 5 g of a NO enhancer, more preferably 0.1 mg to 1 g of a NOenhancer, or more preferably 1 mg to 500 mg of a NO enhancer.

In preferred embodiments, the AV graft is contacted with thecompositions herein for less than 24 hours, more preferably less than240 minutes, more preferably less than 60 minutes, or more preferablyless than 30 minutes. However, in embodiments wherein the compositionsare formulated as perfusate or preservation solutions, the vessels canbe contacted with the compositions for longer periods of time (e.g.,days). If the compositions herein are not formulated as perfusate orpreservation solutions then lesser contact time is preferable.Generally, the contacting step can be performed at any appropriatetemperature, but preferably at a temperature ranging from 0° C. to 40°C., more preferably 2° C. to 30° C., or more preferably 4° C. to 20° C.

The NO enhancers herein can also be used to treat peripheral arterialdisease (PAD). PAD refers to damage to the peripheral arteries, which iscaused by arterial hypertension and/or formation of plaques. Generally,where the arteries are blocked by cholesterol deposits the PAD conditionis also known as atherosclerosis, and where the arteries are blocked bymineral deposits, the condition is known as arteriosclerosis.

PAD is a common disorder that occurs when an artery segment, whichnormally has smooth lining, becomes narrow and rough allowing clots toform on the walls, thus further narrowing the artery. As a result of thearteries narrowing, organs (e.g., brain, heart, legs, kidney) receiveinadequate amounts of blood. This can result in cramping of the organsand/or muscles surrounding the organs. However, some people, especiallythose suffering from type-1 diabetes, do not experience any pain orsymptoms from PAD. This may be referred to as “silent PAD.”

PAD is often diagnosed using any one of the following means: medicalhistory and physical examination, ankle-brachial index (ABI), treadmillexercise test, reactive hyperemia test, segmental pressure measurements,PVR waveform analysis, duplex arterial imaging or ultrasound imaging,photoplethysmography, and arteriogram. Once diagnosed, PAD is oftentreated by life style changes (quit smoking), exercise, drugs (e.g.,Clopidogrel, cilostazol, aspirin and cholesterol lowering drugs), orsurgery. Surgery can involve endarterectomy, which is the opening of theartery, cleaning it, and suturing it back together. Endarterectomy worksbest for pelvis (iliac arteries) or groin (femoral arteries) blockage.Other blockages may be bypassed using a bypass surgery. Bypass surgeriesto treat PAD include, but are not limited to, aortobifemoral (whereinblood routed from the abdominal aortic artery to both femoral arteries),femoropopliteal (wherein blood routed from the femoral to the poplitealartery), and femorotibial (wherein blood routed from the femoral to atibial artery).

For smaller arteries, angioplasty or stenting may be more effective.Angioplasty is widely used for treatment coronary and peripheralarterial disease due to blockage. This procedure is relatively simpleand requires only a small incision in the groin to introduce theinstrument. The instrument is passed through the vessels until itreaches to target region. A balloon at the tip of the instrument is theninflated to compress the plaque and enlarge the artery, thus providingan area for blood to flow through. Thus, the compositions herein can beused in an angioplasty procedure to coat the balloon and/or,potentially, follow-up with localized delivery to the target vessel.Various forms of drug delivery balloons are described in WO92/11895,WO95/05866 and WO96/08286, which are incorporated herein by referencefor all purposes.

In many cases, stenting is preferable to angioplasty. Stents arescaffolds that can be inserted into an artery either prior to, during,or post angioplasty procedure, or as an alternative to an angioplastyprocedure. The present invention contemplates the use of a stent foropening of an artery or a vein in conjunction with the administering ofNO enhancers, preferably arginine polymers, or more preferably argininehomopolymers to the stent area. In preferred embodiments, the NOenhancers are administered locally. Local administration can beaccomplished by any means known in the art, including preferably, theuse of a Dispatch™ catheter, such as the one made by Sci Med, MapleGrove, Minn. The NO enhancers can be administered in vivo and locallyprior to, during, or post stenting or angioplasty.

The NO enhancer can be administered independently or in combination withone or more additional agents. Additional agents that may beadministered include, but are not limited to, paclitaxel, ascomycin,etc.

Recently, the development of coated stents, also known as drug-elutingstents, has allowed for the stent to be coated or imbedded withtimed-release drugs that can prevent restenosis. Thus, the presentinvention contemplates the use of the compositions herein with drugeluting stents to prevent restenosis. In one embodiment, the presentinvention contemplates the use of one or more NO enhancers, preferablyarginine polymers, or more preferably arginine homopolymers to coat astent. Preferably, the NO enhancer composition is formulated for slowrelease. The NO enhancer composition may be imbedded within the stenteither independently or in combination with one or more additionaltherapeutic agents. Effective dosages may widely vary; any dosage thatrestores circulation through a stenosed or restenosed blood vesseland/or alleviates the narrowing of the affected area is acceptable foruse in the invention.

The manner by which the effective compounds are bonded to the stent canalso provide either slow or fast release of the effective compounds.Slow release of the effective compound can take up to ten years.Preferably, the release period that allows for the compositions hereinto be released from the stent or delivery device into the circulation toalleviate narrowing effect. Application of the compositions herein to astent or other local-delivery device can be achieved in a number ofdifferent ways.

First, the compound can be mechanically or electromechanically bonded tothe delivery device, e.g. by a covalent bonding process. When using sucha physical application the compounds are directly embedded into a metalor other suitable substance from which the local-delivery system iscomprised.

Second, the effective composition can also be applied using a chemicalcoating/bonding process, whereby layers of a suitable pharmaceuticalagent, vehicle, or carrier entrap the compound. In this manner, abiological or pharmacological coating already present on thelocal-delivery device acts as a platform for coating the compoundsdescribed above. Examples of platforms include, but are not limited to,silicon carbide, carbon, diamond or diamond-like coating, e.g.polytetrafluoroethylene, hylauronic acid or polyactone. Other suitablesynthetic pharmaceutical agents include, but are not limited to,phosphorylcholine, polyurethane, segmented polyurethane, poly-L-lacticacid, cellulose ester, polyethylene glycol as well as polyphosphateesters. Naturally occurring vehicles or carriers include collagens,laminens, heparins, fibrins, and other naturally occurring substancesthat absorb to cellulose. Using a chemical coating of the stent or otherdevice is particularly advantageous in that it allows the compounds toslowly release from the carrier, vehicle, or agent. This extends thetime that the affected portion of the body sustains the efficaciouseffects of the compounds. The manner in which these carriers or vehiclesinteract with the device material as well as the inherent structure ofthese carriers and vehicles provide a diffusion barrier, therebycontrolling the release of the entrapped compounds. In other words, themanner by which the effective compounds are chemically bonded to thestent or delivery device can control slow or fast delivery of thecompound.

In addition to NO enhancers, additional therapeutic agents may be coatedor imbedded in the stent. Such agents include paclitaxel, ascomycin,etc.

The compositions herein can also be used to treat renal vascularconditions such as malignant nephroangiosclerosis, infarction fromocclusion of major renal vessels, sclerodermna, atheromatousembolization, renal cortical necrosis, renal vein thrombosis,necrotizing arteritis, and Wegener's granulomatosis.

Malignant nephroangiosclerosis appears in most cases as acceleratedcardiovascular disease in the course of idiopathic hypertension,especially in untreated cases. Thus, approximately 20% of patientshaving this condition may also experience renovascular hypertension.Most malignant nephroangiosclerosis cases occur in men during their 40'sand 50's. Malignant nephroangiosclerosis is characterized by fibrinoidnecrosis of arterioles. In particular, interlobular arteries show aconsiderable amount of intimal thickening by a fine concentric layeringof collagen, which may cause a complete obliteration of the vascularlumen. Patients suffering from malignant nephroangiosclerosis are oftenkept alive by kidney dialysis and are often administered anticoagulants.

Renal infraction is a localized area of ischemic necrosis caused byeither renal arterial or venous occlusion, which is usually caused byembolism, arteriosclerotic narrowing, or trauma. Common treatmentsinvolve oercutaneous tranluminal angioplasty or fibrinolytic therapy.Anticoagulants are also administered to many patients.

Atheroembolic renal disease is a condition involving the deteriorationof renal function as caused by atheromatous material obstructing therenal artery. This condition can occur spontaneously or subsequent tovascular surgery or arteriography. Patients suffering from thiscondition are often hypertensive and may experience widespreadperipheral embolism, however there is no diagnosis for this conditionsexcept for by renal biopsy. Furthermore, there are no known treatmentscurrently available for this condition.

Renal cortical necrosis is a rare form of arterial infractioncharacterized by necrosis of cortical tissues with sparing of themedula. Predisposition to this condition involves nephrotoxins, renalischemia, intravascular coagulation, and hyperacute renal allograftrejection. Patients suffering from renal cortical necrosis are generallytreated with kidney dialysis.

Renal vein thrombosis occurs with hypercoagulability. In acute cases,these conditions can be diagnosed using an ultrasonography to detect anenlarged kidney. Furthermore, if a contrast agent is administered theultrasonography shows that no excretion is made. Common treatmentincludes anticoagulant therapy, thrombolytic therapy with streptokinaseor urokinase, and less frequently nephrectomy or surgery is used.

Thus, the present invention contemplates the use of the compositionsherein to treat or prevent renal vascular conditions. For example, oneor more NO enhancers, more preferably an arginine polymer, or morepreferably an arginine homopolymer can be administered in vivo to kidneytissue.

The present invention also contemplates the use of the compositionsherein to treat or prevent pulmonary vascular conditions. Suchconditions include, but are not limited to, atelectasis, acidosis, acutebronchitis, acute mountain sickness, acute pulmonary edema, acutepulmonary thrombolism, adult respiratory distress syndrome, bronchialasthma, emphysema, fat embolism in the lung, heparin protaminereactions, hypertension, hypoxia, hyaline membrane disease, inflammationof the lung, Kartaagener's syndrome, Legionnaire's disease, panacinaremphysema, persistent pulmonary hypertension of newborn, post cardiacsurgery acute pulmonary pneumonia, prenatal aspiration syndrome,pulmonary arterial hypertension, and chronic obstructive pulmonarydisease.

Pulmonary arterial hypertension (PAH) and chromic obstructive pulmonarydisease (COPD) are common pulmonary vascular conditions associated withvasoconstriction. PAH refers to a group of diseases characterized by arise in pressure in the pulmonary artery (the blood vessel that leadsfrom the heart to the lungs) above normal levels. PAH is a severedisease that can become life threatening if undetected or untreated. PAHcan be etiologically divided into two forms: primary pulmonaryhypertension (PPH) refers to pulmonary hypertension occurring in theabsence of a known cause and secondary pulmonary hypertension (SPH)refers to PAH occurring from a known cause.

It is estimated that 1 to 2 individuals per one million suffer from PPH.While PPH affects both genders equally during childhood, after pubertyPPH is more prevalent in women than in men. Currently, about a quarterof all patients suffering from PPH are treated with calciumchannel-blocking drugs that are administered orally. Those who do notrespond to the calcium channel-blockers are placed on continuousintravenous infusion of prostacyclin (a vasodilator). Anticoagulants,diuretics and supplemental oxygen are also used for treatment.

SPH is more common that PPH though largely underdiagnosed. The mostcommon causes for SPH include emphysema and bronchitis. Other causes forSPH include scleroderma, CREST syndrome, and systemic lupuserythematosus. SPH can also be caused by congenital heart diseases,chronic pulmonary thromboembolism, HIV infection, liver disease, anddiet drugs. Treatment of SPH includes correction of the underlying causeand reversal of hypoxemia. Further more, lung transplantation remains anoption for selected patients with pulmonary hypertension that does notrespond to medical management. See Am. Fam. Physician, (2001)63:1789-98, 1800.

COPD is an umbrella name for several lung diseases including asthmaticbronchitis, chronic bronchitis (with normal airflow), chronicobstructive bronchitis, bullous disease, and emphysema. COPD was thefourth leading cause of death in the United States in 1998, accountingfor over 10,000 deaths.

The primary cause for COPD is smoking. Other causes for COPD include aninherited deficiency in an enzyme known as alpha-1-antitrypsindeficiency, industrial pollutants, aerosol sprays, non-tobacco smoke,internal-combustion engine exhaust, and physiological atrophy associatedwith old age (senile emphysema). COPD conditions develop from damage tothe alveoli and the bronchioles, leading to their collapse. When thealveoli collapse, some oxygen stays in the lung and becomes “stale.”Other parts of the lung must substitute for the collapsed alveoli,leading to over-inflation, inflammation of the lungs, and a feeling ofshortness of breath.

The most important treatment of COPD is the cession of smoking. Otherdrug treatments include fast-acting beta-2-agonists (e.g., albuterol)and anticholinergic bronchodilators (e.g., ipratropium bromide andtheophylline derivatives) to open airways. In addition, long-actingbronchodilators can also be used to relieve constriction of airways andprevent bronchospasm associated with COPD. Inhaled or oralcorticosteroids may be administered to help reduce inflammation.Antibiotics may be administered to prevent further damage by infection.Expectorants may be administered to help loosen and expel mucussecretions from the airways. Diuretics may be administered to reduceaccess water retention associated with right-heart failure that occursin some COPD patients. Digitalis (usually in the form of digoxin) may beadministered to strengthen the force of the heartbeat. Other treatmentsincluding painkillers, cough suppressants, and sleeping pills, may beadministered to depress breathing.

Thus the current invention contemplates the use of NO enhancers, morepreferably arginine polymers, and more preferably arginine homopolymersin the treatment and/or prevention of pulmonary vascular conditions,including PAH and COPD. In preferred embodiments, the NO enhancers areformulated as aerosols or solutions for direct administration (e.g., viainhalation or via a bronchoscope) to the alveoli and bronchioles. The NOenhancers can be administered independently or co-administered with oneor more additional therapeutic agents disclosed herein (e.g.,corticosteroids, antibiotics, expectorants, diuretics, digitalis, etc.).

It is also contemplated by the present invention that vascularconditions associated with sexual dysfunction may be treated and/orprevented with the compositions herein. Vascular conditions associatedwith sexual dysfunction include, but are not limited to, erectiledysfunction, Peyronie's syndrome, priapism, premature ejaculation,female sexual dysfunction, vaginal lubrication, vaginal engorgement,pain during intercourse (e.g., dyspareunia or vulvadynia), preeclampsia,urologenital infections, vulvodynia and estrogen depletion conditionssuch as menopause, post-menopause, and hot flashes.

In one example, the present invention contemplates the use of thecompositions herein for the treatment of erectile dysfunction. Erectiledysfunction is a vascular condition whose symptoms include the totalinability to achieve erection, an inconsistent ability to do so, and atendency to sustain only brief erections. It is estimated that 15-30million Americans suffer from erectile dysfunction. While the incidenceof erectile dysfunction increases with age (about 5% of 40-year-old menand 15-25% of 65-year-old men experience erectile dysfunction), erectiledysfunction is usually caused by disease, injury, or side effects fromother drugs and not age.

Treatment for erectile dysfunction varies from least invasive,psychotherapy, to most invasive, surgery. However, most erectiledysfunction cases are treated using drugs that can be taken orally,injected directly into the penis, or inserted into the urethra at thetip of the penis. An alternative treatment provides a mechanical vacuumdevice that can be used to cause an erection by creating a partialvacuum, which draws blood into the penis, engorging and expanding it.

The current invention contemplates the use of NO enhancers for thetreatment and/or of sexual dysfunction vascular conditions, includingerectile dysfunction. Thus a patient suffering from erectile dysfunctionmay be administered an NO enhancer, more preferably an arginine polymer,and more preferably an arginine homopolymer. Preferably, the NO enhanceris administered locally, e.g. by topical application or subcutaneousapplication. For topical application, the NO enhancer may be formulatedas a gel or as a solution that can be applied locally to the penilearterial blood vessel and/or the trabecular meshwork. For subcutaneousadministration the NO enhancer may be formulated as a solid, solution,or gel. The NO enhancer can be administered independently orco-administered with additional therapeutic agents that increase bloodflow into the cavernous bodies of the penis.

In another example, the present invention contemplates the use of thecompositions herein for the treatment of vulvodynia. Vulvodynia (alsoknown as vulvar dysesthesia) is characterized by itching, burning,stinging or stabbing sensations in the area around the opening of thevagina. Symptoms of vulvodynia may range from mildly irritating tocompletely disabling. While a distinct sore or area of redness may bevisible, often the vagina shows no abnormalities or infections ongynecological and/or dermatological evaluations. It is estimated thatfive percent of all women will experience vulvodynia before the age 25.However, until recently, there have been no drug treatments forvulvodynia. Instead, patients diagnosed with this condition areprescribed dietary changes, vitamin supplements, muscle relaxants,biofeedback therapy, electrical stimulation, and psychotherapy. SeeNewman, Ostomy. Wound. Manage. (2000) 46(12):48-54.

Recently, it has been suggested that vulvodynia is caused by abnormalityin the muscles of the pelvic floor. See Glazer H I, J. Reprod. Med.(2000) 45(10):798-802. As a result, some are experimenting withtreatment using botulinum toxin (botox) injections. Botox is a toxin,which causes muscle paralysis when injected. In women suffering fromvulvodynia, botox may be injected into pelvic walls to reduce musclecontractions and/or muscle pain.

The present invention contemplates the use of NO enhancers, morepreferably arginine polymers, and more preferably arginine homopolymersfor the treatment and/or prevention of vulvodynia. Preferably, NOenhancers (e.g., poly-L-arginine and R9) are formulated for localizedapplication. For example, a NO enhancer can be formulated into a gel oran ointment and applied vaginally to the pelvic walls.

In one example, a NO enhancer is formulated as a solid suppository or agel and administered vaginally or subcutaneously. Preferably, the NOenhancer is formulated for slow release. Formulations of thecompositions herein may be admixed with additional therapeutic agentssuch as muscle-relaxers or painkillers. Alternatively, a treatmentregimen may include separate applications of NO enhancers and additionaltherapeutic agents.

Ocular vascular conditions that can be treated and/or prevented with thecompositions herein include, but are not limited to, cataract,intraocular pressure, dry eye, diabetic retinopathy, and glaucoma.Glaucoma is an ocular vascular conditions associated withvasoconstriction causing a particular pattern of optic nerve damage.While this pattern of damage usually occurs as a result of increasedintraocular pressure, it may also occur with normal or even below-normalocular pressure.

Worldwide, it is estimated that about 50 million people suffer fromglaucoma. In the United States, there are more than three million peoplediagnosed with glaucoma and about 300,000 new cases are diagnosed eachyear. Glaucoma's effects can range from mild vision impairment tocomplete blindness. Unfortunately, many of those affected by glaucomamay not be aware of the disease as its early stage symptoms may not beeasily apparent. By the time a patient exhibits ocular conditionsassociated with the disease, considerable damage has already occurred.Medications and surgery can help slow down the progression of glaucomabut they cannot cure vision lost.

Glaucoma is generally divided into two forms: primary and secondary.There are two types of primary glaucoma: (1) chronic open-angle and (2)acute or chronic angle-closure glaucoma. Chronic open angle glaucoma(COAG) is the most prevalent form of glaucoma and accounts for nearly85% of all cases. COAG is caused by malfunctioning of the drainagesystem between the anterior and posterior chambers of the eye. In ahealthy eye, aqueous humor is formed in the posterior chamber of the eyeby the ciliary body and processes at a rate of approximately 2.5microliters per minute. The humor then passes around the lens, throughthe papillary opening in the iris, and into the anterior chamber of theeye. The aqueous humor drains out of the eye via either a “uveoseleral”route or a “canalicular” route. The uveoscleral route involves drainagebetween the muscle fibers of the ciliary body and accounts forapproximately 15-20% of aqueous drainage. The canalicular route involvesdrainage thought the trabecular meshwork into the Schlemm's canal. Theproduction of humor in a healthy eye is equal to aqueous outflow andintraocular pressure remains fairly constant in the range of 10 to 20mmHg.

In COAG, there is an abnormal resistance along the outer aspect of thetrabecular meshwork and the inner wall of the Schlemm's canal. It isbelieved that this resistance is a result of abnormal metabolism of thetrabecular cells leading to an excessive buildup of extracellularmaterial or a buildup of abnormally “stiff” materials in this region. Asfluid builds up due to reduced drainage of aqueous humor, the pressureinside the eye, referred to herein as intraocular pressure (IOP) rises.Unless IOP is controlled, the increased pressure can lead to damage theoptic nerve, resulting in progressive visual loss and even blindness.

Agents that have been suggested in the topical treatment of COAG includepilocarpine, timolol maleate, betataxolol HCl, epinephrine, dipivefrin,demecarium bromide, echothiophate iodide. See Merck Manual, (15^(th) Ed.Merck Sharp & Dohme Research Labs. 1987). Systemic agents administeredto treat COAG include carbonic anydrase inhibitors. Other agents havealso been suggested to the treatment of COAG. See EP 257887 (alkaloids);EP 291999A2 (atrial natriuretic factor peptides); U.S. Pat. No.4,722,933 (substituted 2-aminotetralins); U.S. Pat. No. 4,515,800(phenylimino-imidazoles); U.S. Pat. No. 4,694,022 (betaxolol salts);U.S. Publication Application No. 2002/0168424 (NO donors such asminoxidil, nitroglycerin, monomeric L-arginine, isosorbide dinitrate andnitroprusside in combination with a cyclic guanosine 3′,5′-monophosphatespecific phosphodiesterase type 5 (cGMP-PDE5) inhibitor); U.S.Publication Application No. 2003/0153626 (A3 subtype adenosine receptorantagonists, calmodulin antagonists and antiestrogens); U.S. PublicationApplication No. 2003/0153613 (potassium channel blockers); U.S.Publication Application No. 2003/0153501 (oncomodulin and a cAMPmodulator); and U.S. Publication Application No. 2003/0060511(15-keto-prostaglandin compound).

Acute angle-closure glaucoma (AACG) and chronic-angle-closure glaucoma(CACG) are characterized by attacks of sudden increased IOP, usuallyunilateral, with severe pain and loss of vision, caused by acuteobstruction of acquires drainage with the eye. Such conditions aretreated with compositions used to treat COAG. Secondary glaucoma, on theother hand, is a condition caused by other disorders or conditions suchas intraocular tumors, intumescent cataracts, central retinal veinocclusion, trauma to the eye, operative procedures, inflammatorydisease, and intraocular hemorrhage, which result in complete posteriorsynechia and iris bombe. Treatment of secondary glaucoma usuallyinvolves treating the underlying cause.

The current invention contemplates the use of NO enhancers, morepreferably arginine polymers, and more preferably arginine homopolymersfor the treatment and/or prevention of vascular ocular conditionsincluding glaucoma. Preferably, a poly-L-arginine or an R9 compositionis administered directly to the target tissue (e.g., outer aspect of thetrabecular meshwork or inner walls of the Schlemm's canal). Directadministration can be accomplished, for example, by topical applicationor by localized microinjections. The NO enhancers can be administeredindependently or co-administered with one or more additional therapeuticagents disclosed herein.

It is also contemplated that the compositions herein may be used totreat dermal vascular conditions including, but are not limited to, skinaging, necrotizing fascitis, decubitus ulcers, anal fissures, Raynaud'sphenomenon, scleroderma, hair loss (e.g., Alopecia Areata, hair loss inpatches believed to be an immunologic disorders Alopecia Totalis, hairloss over the entire scalp, Alopecia Universalis, loss of all hair, allover the body, Anagen Effluvium, sudden loss of growing hairs which isoften caused by chemotherapy, Telogen Effluvium, sudden hair loss whenlarge numbers of follicles enter the resting phase which is usuallytemporary and may be caused by severe stress, medications, etc.),diffused cutaneous systemic sclerosis, frostbites, and wound healing.

Wound healing involves the repair and reconstruction of tissue, e.g.;skin, muscle, neurological tissue, bone, soft tissue, internal organs,and vascular tissue. Wounds are generally categorized into four stages.Stage I wounds are characterized by redness or discoloration, warmth,and swelling or hardness. Stage II wounds partially penetrate the skin.Stage III wounds describe full-thickness wounds that do not penetratethe tough white membrane (fascia) separating the skin and fat from thedeeper tissues. Stage IV wounds involve damage to muscle or bone andundermining of adjacent tissue. Stage IV wounds may also involve thesinus tracts (red streaks indicating infected lymph vessels).

Wounds can result from either acute or chronic injury. Chronic woundsare a frequent problem for elderly and bedfast patients. An ulcer or awound is an open sore on the skin (or a mucous membrane) that causesdestruction of the surface tissue. An ulcer can be shallow or deep andis usually inflamed and painful. There are numerous types of ulcersincluding, for example, traumatic ulcers, arterial ulcers, venousulcers, diabetic foot ulcers, and pressure ulcers. Burns are anotherform of wounds.

Generally, wounds heal in the following three stages: inflammation,proliferation and maturation. The inflammation stage occurs in theinitial days following an injury. During inflammation, the wound areaattempts to restore homeostasis by constricting blood vessels to controlbleeding, releasing platelets and thromboplastin to generate a clot, andreleasing cytokines to generate an inflammatory response. Next, in theproliferation stage, granulation occurs. Granulation involvesepithelialization (growth of new skin), angiogenesis (blood vesselregeneration), and generation of new collagen by fibroblast cells.Granulation can last 3 weeks or longer depending on the severity of thewound. Finally, in the maturation stage, new collagen forms, changingthe shape of the wound and increasing strength of tissue in the area.This often forms a scar. The maturation stage can last for up to 2years.

Wound healing generally does not respond to conventional treatments thatare used to treat superficial cuts. Currently, there are no specifictreatments to wound healing aside from keeping the area moist andproviding to the area nutrients, including angiostatic steroids, sexsteroids, bromelain, vitamin B-complex, vitamins A, E and C, zinc,chondroitin insulfate, copper, ornithine alpha-ketoglutarate (OKG),arginine monomers, carnosine, and glucosamine sulfate.

Thus, the present invention contemplates the use of NO enhancers,preferably arginine polymers, and more preferably arginine homopolymers,for the treatment and enhancement of wound healing. Preferable the NOenhancers are administered topically to the wound region. Formulationsfor topical administration are disclosed herein. The number ofapplications per treatment cycle may vary according to the severity ofthe wound and may be determined by a physician. The NO enhancers can beadministered independently or co-administered with additionaltherapeutic agents or nutrients (e.g. steroids, vitamins, minerals andtrovafloxacin).

Similar to wound healing, the present invention also contemplates theuse of NO enhancer(s) for the treatment of frostbites. Frostbite is aninjury caused by exposure to cold temperatures, which does notnecessarily need to be below freezing. The cold temperature causes icecrystals and clots to form and can result in poor perfusion to the faceand the extremities, leading to dehydration and cell death. If theexposure continues, damage may occur to underlying blood vessels,nerves, and muscles.

When patients receive medical care quickly, frostbite is oftenreversible because the injury is less severe. If treatment is delayed,patients may have long-term medical problems. The NO enhancers hereincan be helpful in the reperfusion of vessels injured by frostbites.Thus, the present invention contemplates the use of NO enhancers,preferably arginine polymers, and more preferably arginine homopolymers,for the treatment of frostbites. The NO enhancer(s) are preferablyformulated for localized administration (e.g., topical administration ofa gel or a solution). The compositions herein can further includeadditional therapeutic agents, such as, for example, reserpine, pitviper venom, phenoxybenzamine, heparin, and dextran. Other forms ofreperfusion injury follow cerebral vascular accidents or myocardialinfarction and may be amenable to treatment with NO enhancers in asimilar manner. Thus, the present invention contemplates the use of NOenhancers for the prevention and/or treatment of instances where bloodflow begins anew to hypoxic tissues.

In another embodiment the present invention contemplates the use of thecompositions herein for the treatment of anal fissures. Anal fissuresare breaks in the skin that lines the anal canal. While mild cases ofanal fissures involve only superficial tear in the tissue that lines theanal canal, these tears can deepen and reach underlying tissue of theinternal sphincter. Anal fissures occur mostly in young people, andgenerally as a result of passage of a hard stool that traumatizes theanus. Most patients who develop anal fissures have a higher than normalpressure in the anal canal. In a small percentage of cases, analfissures stem from other causes, such as Crohn's disease or certaininfections. Currently, treatment of anal fissures includes sitz baths,suppositories or stool bulking agents to treat constipation, and topicalnitroglycerin ointment to alleviate pain. It has been suggested thatcompounds that release NO, such as nitroglycerin, ethylene glycoldinitrate, glyceryl 1,2-dinitrate, glyceryl, 1,3-dinitrate, glyceryl1-mononitrate, butane 1,2,4-triol-triinitrate, mannitol hexanitrate,pentaerythrityl tetranitrate, pentaerythrityl trinitrate, isosorbidedinitrate, isosorbide mononitrate, and erythrityl tetranitrate may beused for the treatment of anal fissures. See U.S. Pat. No. 5,504,117(incorporated herein by reference for all purposes). However, severeanal fissures may require surgical therapy as an alternative or inaddition to drug treatment. Recently, anal fissures have been treatedwith botox injected into the anal sphincter to lower the pressure andallow the fissures to heal.

The present invention contemplates the use of NO enhancers, morepreferably arginine polymers, and more preferably arginine homopolymersfor the treatment and/or prevention of anal canal disorders includinganal fissures. In particular, the present invention contemplates apharmaceutical composition comprising an active ingredient argininehomopolymer, e.g. R9, for the treatment/prevention of anal fissures,anal ulcers, and levator spasm. In some embodiments, the pharmaceuticalcompositions are formulated for topical administration. In otherembodiments, the pharmaceutical compositions are formulated forsubcutaneous administration (e.g., via a microinjection).

The compositions may be co-administered with additional therapeuticagents, including, for example, painkillers, antibacterial, antifungal,and anti-inflammatories. In one example, a suppository of both a R9polymer and an anesthetic composition is formulated into a gel, cream orsolution and administered rectally to a patient suffering from analfissures.

The invention herein also contemplates the local administration ofcompositions that increase the metabolic production of NO for thetreatment of Raynaud's phenomenon. Raynaud's phenomenon is a conditionin which circulation of blood to the extremities is interrupted. Thisusually occurs as a result of touching cold objects, exposure to cold,emotions, and smoking. However, people who work with vibratory tools arealso prone to Raynaud's phenomenon, Raynaud's can range in severity fromminor discomfort to the onset of ulcers or even gangrene. Raynaud'soften starts at young age and progresses slowly over thirty years ormore. Primary Raynaud's occurs spontaneously without an underlyingcondition being present. Raynaud's affects women nearly ten times morethan men. There is some suggestion that primary Raynaud's is hereditary.Secondary Raynaud's is less common the primary Raynaud's and isassociated with an underlying disease, e.g., scleroderma, systemic lupuserythematosus, Sjögrens syndrome and rheumatoid arthritis. This is moreserious and early and accurate diagnosis is essential.

Scleroderma, another dermal vascular condition, is symptomatic wheneither external skin or an internal organ becomes stiff, tight, andshiny due to swelling or thickening of the connective tissue.Approximately 300,000 individuals in the United States have scleroderma.Scleroderma, like Raynaud's phenomenon, is more common in women than inmen. Internal organs that are commonly affected by scleroderma includethe esophagus, gastrointestinal tract, lungs, kidneys, and heart.Scleroderma may also affect blood vessels, muscles and joints.Currently, there are no known treatments for scleroderma.

According to the present invention, NO enhancers, more preferablyarginine polymers, and more preferably arginine homopolymers, are usedto treat and/or prevent dermal vascular conditions including Raynaud'sand scleroderma. Preferably, the NO enhancers are administered topicallyor subcutaneously to the affected areas. For topical administration, theNO enhancers are formulated as gels, ointments, creams, and lotions. Forsubcutaneous administration, the NO enhancers are formulated assolutions or gels. For example, a patient suffering from Raynaud's orscleroderma may be administered a therapeutically effective amount of aNO enhancer (e.g., R9 or a poly-L-arginine) by topically applying asolution or gel comprising the NO enhancer. The NO enhancers can beadministered independently or in combination with one or moretherapeutic agents, e.g., a painkiller or a corticosteroid.

III. Formulations and Use

The compositions herein may be formulated into pharmaceuticallyacceptable salts and/or complexes thereof. Pharmaceutically acceptablesalts are non-toxic salts at the concentration at which they areadministered. The preparation of such salts can facilitate thepharmacological use by altering the physical-chemical characteristics ofthe composition without preventing the composition from exerting itsphysiological effect. Examples of useful alterations in physicalproperties include lowering the melting point to facilitate transmucosaladministration and increasing the solubility to facilitate theadministration of higher concentrations of the drug.

Pharmaceutically acceptable salts include acid addition salts such asthose containing sulfate, hydrochloride, phosphate, sulfonate,sulfamate, sulfate, acetate, citrate, lactate, tartrate,methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate,cycloexylsulfonate, cyclohexylsulfamate, and quinate. Pharmaceuticallyacceptable salts can be obtained from acids such as hydrochloric acid,sulfuric acid, phosphoric acid, sulfonic acid, sulfamic acid, aceticacid, citric acid, lactic acid, tartaric acid, malonic acid,methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid,p-toluenesulfonic acid, cyclohexylsulfonic acid, cyclohexylsulfamicacid, and quinic acid. Such salts may be prepared by, for example,reacting the free acid or base forms of the product with one or moreequivalents of the appropriate base or acid in a solvent or medium inwhich the salt is insoluble, or in a solvent such as water which is thenremoved in vacuo or by freeze-drying or by exchanging the ions of anexisting salt for another ion on a suitable ion exchange resin.

Pharmaceutical compositions can be formulated from active compositionsand/or salts thereof by standard techniques using one or more suitablecarriers, excipients, and diluents. See, e.g., Remington'sPharmaceutical Sciences, (19^(th) Ed. Williams & Wilkins, 1995)(incorporated herein by reference for all purposes).

Examples of suitable carriers, excipients and diluents include lactose,dextrose, sucrose, sorbitol, mannitol, starches, gum acacia, calciumphosphate, alginates, calcium silicate, microcrystalline cellulose,polyvinyl pyrrolidine, cellulose, tragacanth, gelatin syrup,methylcellulose, methyl and propyl hydroxybenzoates, talc, magnesiumstearate, water and mineral oil. Other additives optionally includelubricating agents, wetting agents, emulsifying and suspending agents orpreserving agents. An ophthalmic carrier is preferable in sterile,substantially isotonic aqueous solutions. Such solutions will typicallymaintain sterility by employing well-known ophthalmic preservatives. Theamount of these preservatives employed is generally about 0.001 to 0.1%by weight. Particularly suitable preservatives for ointments includemethyl and propyl parabens.

The pharmaceutical compositions may be formulated to provide immediate,sustained or delayed release of the compound. For applications providingslow release, certain carriers may be particularly preferred. Suitableslow release carriers may be formulated from dextrose, dextran,polylactic acid, and various cellulose derivatives, for exampleethylhydroxycellulose in the form of microcapsules.

Various additives may be added to the formulations herein. Suchadditives include substances that serve for emulsification,preservation, wetting, improving consistency and so forth and which areconventionally employed in pharmaceutical preparations. Other additivesinclude compounds that have surfactant properties, either ionic ornon-ionic such as sorbitan monolaurate triethanolamine oleate,polyoxyethylenesorbitan monopalmitate, dioctyl sodium sulfosuccinate,monothioglycerol, thiosorbitol, ethylenediamine tetra-acetic acid, etc.

Suitable preservatives for use in the pharmaceutical preparationsinclude benzalkonium chloride, benzethonium, phenylethyl alcohol,chlorobutanol, thimerosal and the like. Suitable buffers include boricacid, sodium and potassium bicarbonate, sodium and potassium borates,sodium and potassium carbonate, sodium acetate, sodium biphosphate,Tris, and the like, in amounts sufficient to maintain the pH betweenabout pH 3 and about pH 9.5, most preferably between about pH 7 and pH7.5. Suitable tonicity agents are dextran 40, dextran 70, dextrose,glycerin, potassium chloride, propylene glycol, sodium chloride and thelike, such that the sodium chloride equivalent of the ophthalmicsolution is in the range of 9.9.+−.0.2%.

Suitable antioxidant and stabilizers include sodium and potassiumbisulfite, sodium and potassium metabisulfite, sodium thiosulfate,thiourea and the like. Suitable wetting and clarifying agents includepolysorbate 80, polysorbate 20, poloxamer 282 and tyloxapol. Suitableviscosity increasing agents include dextran 40, gelatin, glycerin,hydroxyethyl cellulose, hydroxymethyl propyl cellulose, lanolin,methylcellulose, petrolatum, polyethylene glycol, polyvinyl alcohol,polyvinyl polyvinylpyrrolidone, carboxymethyl cellulose and the like.Stabilizers such as chelating agents that may be used include, forexample, EDTA, EGTA, DTPA, DOTA, ethylene diamine, bipyridine,1,10-phenanthrolene, crown ethers, aza crown, catechols, dimercaprot,D-penicillamine and deferoxamine. Antioxidants that may also act asstabilizers include such compounds as ascorbic acid, sodium bisulfite,ascorbyl palmitate, butylated hydroxyanisole, butylated hydroxytoluene,potassium metabisulfite and sodium metabisulfite.

Antibacterial, antiviral, antifungal and anti-tumor agents may also beused in the pharmaceutical compositions herein. Such agents and theirformulations are well known to those skilled in the art.

Viscosity agents are often added to prevent extensive drug loss bydrainage once an aqueous preparation is instilled in the eye. Severalcompounds are suitable for this purpose, including methylcellulose,hydroxypropylmethylcellulose, polyvinyl alcohol, dextran, andhydroxyethylcellulose (Ludwig and Van Ooteghem, 1989).

The pharmaceutical compositions can be administered orally, parenterallyby inhalation, topically, rectally, ocularly, nasally, buccally,vaginally, sublingually, transbuccally, liposomally, via an implantedreservoir (e.g., patch or stent) or via local delivery (e.g., bycatheter). The term “parenteral” as used herein includes subcutaneous,intracutaneous, intravenous, intramuscular, intra-articular,intra-adipose, intra-arterial, intrasynovial, intrasternal, intrathecal,intra-vagina, intra-rectal, intralesional, intra-ocular, andintracranial injection or infusion techniques. Preferably, thepharmaceutical compositions are administered locally to effected area ortissue.

Ointment may be formulated with cetyl ester waxes, oleic acid, paraffin,petrolatum, hydrophilic petrolatum or white petrolatum. Other ointmentcomponents may include mineral oil, lanolin, anhydrous lanolin, glycerolmonosteate or cetyl alcohol. Water-soluble ointment bases and componentsmay incorporate glycol ethers and their derivatives, polyethyleneglycols, polyoxyl 40 stearate and polysorbates.

Solid inserts for localized delivery (e.g., to the eye, vagina, rectumand penis) may also be employed. Such inserts will be in suitable formfor the target area to be inserted. For example, an ocular insert may bein suitable form to be inserted into an area of the eye known as the culde sac (a pocket-like area formed with the conjunctiva). Such an insertmay include one or more active ingredients and may be biodegradable ornon-biodegradable. In administering solids into the eye area,consideration should be given in the choice of biodegradable material asit may be affected by tears and lacrimal fluids. Inserts into the rectumand vagina may be in the form of a suppository or retention enemas. Suchinserts may contain conventions suppository bases such as cocoa butteror other glycerides. Inserts into the urethra may be in the form of atablet, suppository or other pill that may include biodegradeable and/ornonbiodegradeable materials.

Pharmaceutical compositions may also be formulated for depotpreparations or slow release preparations. Such preparations can beadministered by implementation (e.g., subcutaneously, intravaginally,intraocularly, intradermally, or intramuscularly) or by localizedinjections (e.g., subcutaneous).

Liposomal preparations are also contemplated by the present invention.One could incorporate the pharmaceutical compositions herein intovarious liposomes by mixing with the appropriate lipids orphospholipids.

The pharmaceutical compositions may be delivered using drug deliverysystems. Such delivery systems include hyaluronic acid solutions orsuspensions of collagen fragments. The drugs may be formulated inmicrocapsules, designed with appropriate polymeric materials forcontrolled release, such as polylactic acid, ethylhydroxycellulose,polycaprolactone, polycaprolactone diol, polylysine, polyglycolic,polymaleic acid, poly[N-(2-hydroxypropyl)methylacrylamide] and the like.Particular formations may be in the form of liquid suspensions,ointments, complexes to a bandage, collagen shield or the like. In somecases, for example where there is existing damage to the cornea, thecompositions may be administered intradermally or possiblysubcutaneously.

Administration into the eye is preferably via topical applications usingeye drops, ointments, aerosols, or solid inserts. Eye drops and eyeointments are easily administered to the eye topically and have a rapideffect on target region. Another form of administration ismicroinjection into the eye of solubilized compounds. For example,microinjections can be made into a site near the trabecular meshwork orthe Schlemm's canal. Microinjection is preferable to avoid side effectsresulting from generalized exposure of the eye to a pharmaceuticalcompound. Microinjection may be used for infrequent administration, forexample, weekly, biweekly, every few weeks, months, or even years, incontrast to the more frequent administrations required in the case oftopical administration. Other forms of administration include tablets,capsules, powders, granules, etc. which may be administered orally andmay have side effects or longer duration before efficacy.

Administration into the airways is preferably via inhalation or viaphysical application, using aerosols, solutions, and devices such as abronchoscope. For inhalation, the compositions herein are convenientlydelivered from an insufflator, a nebulizer, a pump, a pressurized pack,or other convenient means of delivering an aerosol, non-aerosol spray ofa powder, or noon-aerosol spray of a liquid. Pressurized packs maycomprise a suitable propellant such a liquefied gas or a compressed gas.Liquefied gases include, for example, fluorinated chlorinatedhydrocarbons, hydrochlorofluorocarbons, hydrochlorocarbons,hydrocarbons, and hydrocarbon ethers. Compressed gases include, forexample, nitrogen, nitrous oxide, and carbon dioxide. In particular, theuse of dichlorodifluoromethane, trichlorofluoromethane,dichlorotetrafluoroethane, carbon dioxide or other suitable gas iscontemplated. In the case of a pressurized aerosol, the dosage unit maybe determined by providing a valve to deliver a controlled amount. Inadministering a dry powder composition, the powder mix may include asuitable powder base such as lactose or starch. The powder compositionmay be presented in unit dosage form such as, for example, capsules,cartridges, or blister packs from which the powder may be administeredwith the aid of an inhalator or insufflator.

Administration to the vagina is preferably made via topical, vaginalapplications, subcutaneous applications, or via microinjections into anaffected area. The pharmaceutical compositions applied to the vagina maybe in the form of a gel, cream, foam, ointment, aerosol, capsule, fluid,powder or suppository. Vaginal compositions may be administered directlyto the target area (e.g., pelvic wall) or via an intravaginal devicefrom which the composition is released. Administration to the vagina ispreferably made in a time-release manner. The composition herein arepreferably attached to a lipophilic or hydrophilic carrier andformulated in combination with a mucoadhesive agent to enhanceadhesivity of the released compound to the vaginal mucosa and to assurecontact with the vaginal mucosa. In order to enhance absorption of thecompositions through the vaginal mucosa, an absorption enhancer orpenetration promoter for intravaginally administered compounds isutilized as another formulating agent.

Administration to the rectum is preferably made via topical, rectal,and/or microinjections. Topical and rectal preparations are preferablyformulated as suppositories with an oily excipient, such as cocoabutter. Microinjections are prepared as solutions and preferablyformulated for slow release.

Amounts of pharmaceutical composition administered can vary, accordingto determinations made by one of skill, but preferably such amounts areeffective to create an increase in the effective amount of L-arginine,increase in the effective amount of NO, and/or an increase in dilatoryeffect at the desired site without causing severe system hypotension.Furthermore, the amounts of composition administered may vary dependingupon the individual, the condition being treated, the target site,additional agents in the composition or in treatment regimen, and theroute by which the compositions are administered, all of which can bederived empirically according to methods known in the art.

In some embodiments, the compositions herein are co-administered withone or more additional therapeutic agents. Combination therapiesaccording to this invention exert a synergistic effect of increasing NOin a cell, tissue and/or organ, or may act by an independent mechanismto treat the targeted condition. The use of such combinations is alsoadvantageous to reduce the dosage of a given conventional therapeuticagent that would be required for a desired therapeutic or prophylacticeffect as compared to when that agent is administered as a monotherapy.Combinations treatments may also reduce or eliminate the side effects ofconventional single agent therapies. Combinations may also increase theefficacy of a conventional agent without increasing the associatedtoxicity. Preferred combination therapies include the administration ofa compound of this invention with anti-inflammatories, antibiotics,diuretics, vasodilators, E2F Decoy, antiproliferatives, NO donors and NOreleasing agents. When the compositions of this invention areadministered in combination therapies with other agents, they may beadministered sequentially or concurrently with such other agents to thepatient.

As used herein a therapeutically effective amount is an amount, whichupon a single or multiple doses produces a desired therapeutic effect bysignificantly increasing the levels of NO or L-arginine in a cell,tissue and/or organ. The dosages of NO enhancers used herein may varydepending upon the requirements of the patient in the judgment of theattending clinician, the severity of the condition being treated, andthe particular compound being employed. In determining thetherapeutically effective amount or dose of a NO enhancer(s), a numberof factors should be considered by the attending clinician, including,but not limited to: the specific condition being treated, thepharmacodynamic characteristics of the particular compound beingadministered, the mode and route of administration, the desired timecourse of treatment, the species of mammal being treated, its size, ageand general health, the degree of or involvement or severity of thedisease, the response of the individual patient, the particular compoundadministered, the bioavailability characteristics of the preparationadministered, the dose regimen selected, concurrent treatment (i.e.,other co-administered therapeutic agents), and other relevantcircumstances.

Generally, formulations of NO enhancers have a NO enhancer concentrationof about 0.001 μM-100 mM, more preferably of about 0.01 μM-10 mM, morepreferably of about 0.1 μM 1 mM, or more preferably of about 1 μM-500μM. In some embodiments, formulations of NO enhancers are between 0.001mg/ml-10 g/ml NO enhancer(s), more preferably 0.01 mg/ml-5 g/ml NOenhancer(s), more preferably 0.1 mg/ml-1 g/ml NO enhancer(s), or morepreferably 1 mg/ml-500 mg/ml NO enhancer(s).

Of course, the concentration of NO enhancers may be higher or lower thanany of the above dosages. The concentration of arginine polymers and/orhomopolymers will depend, in part, on the percentage of L-argininesubunits and D-arginine subunits as well as other amino acid residues inthe polymer.

The NO enhancers can be administered once or multiple times. Multipleadministrations can be performed at intervals ranging from hourly,daily, weekly, biweekly, monthly, biyearly, yearly. However, intervalscan also be more or less frequent than the above.

Upon improvement of a patient's condition, a maintenance dose of acomposition or combination of this invention may be administered ifnecessary. Subsequently, the dosage or frequency of administration, orboth, may be reduced, as a function of the symptoms, to a level at whichthe improved condition is retained. When the symptoms have beenalleviated to the desired level, treatment may cease or patients mayrequire intermittent treatment on a long-term basis.

As the skilled artisan will appreciate, lower or higher doses than thoserecited above may be required. Specific dosage and treatment regimen forany particular patient will depend upon a variety of factors, includingtype, severity and course of the condition afflicting the patient; theactivity of the specific composition employed, the age, sex, body, diet,weight, and general health status of the patient; the time, frequency,and route of administration; the patient's rate of excretion, and drugcombination effects.

EXAMPLES

The following examples illustrate embodiments of the present invention.

Example 1

An AV graft is contacted with in a solution containing 0.001 μM-100 mmNO enhancer(s), e.g., R9 or R10. The graft is contacted with thesolution for a period preferably less than 60 minutes. The graft iscontacted prior to, during, and/or post grafting. In some cases, thegraft is infused intraluminally with the L-arginine solution and one orboth ends of the graft are clamped such that only the intraluminal wallsof the vessel are contacted.

Example 2

An organ transplant solution (perfusate) preferably includes 0.001μM-100 mM of a NO enhancer(s), e.g., R9 or R10. Furthermore, thesolution may also include approximately 1-5% by weight hydroxyethylstarch. The solution can have a molecular weight ranging preferablybetween 150,000-350,000 Daltons. The solution can have an osmolalitylevel ranging preferably between 100-500 mOsm/liter. Other agents thatmay be admixed into the solution include, but are not limited to,lactobionate salt, raffinose, electrolytes, glutathione, potassiumphosphate, magnesium gluconate, adenosine, insulin, bactrim,dexamethasone, allopurinaol and other anti-inflammatory, antibiotic,anti-metabolic, and anti-neoplastic agents

Example 3

For the treatment of peripheral arterial disease, a drug eluting stentmay be coated or immersed with a timed-release NO enhancer, e.g. anarginine homopolymer containing L-arginines, D-arginines, or acombination thereof. An additional slow release carrier or excipient maybe admixed with the polyarginine. Alternatively, a stent or balloon canbe inserted into the targeted area (an occlusion), and a Dispatchcatheter can deliver locally and in vivo a composition of R9 (SEQ. IDNO. 2) (e.g., a solution of 0.001 .mu.-100 mM R9 (SEQ. ID NO. 2)) priorto, during, and/or post stenting or angioplasty.

Example 4

A graft used for CABG may be immersed ex vivo in a solution comprisingof 0.001μ-100 mM of a NO enhancer, e.g., R9, for 10-20 minutes at roomtemperature. The solution can be either serum free culture media (e.g.,DMEM) or aqueous saline NaCl solution (e.g., 0.5-2.0% (w/v) saline.Alternatively, a graft may be immersed ex vivo in any of the transplantor perfusate solutions disclosed herein. Furthermore, a graft can becontacted with any of the above solutions in vivo either prior itsexcision from a body or post transplantation.

Example 5

A female diagnosed with vulvodynia is treated with one or moremicroinjections of a solution comprising a NO enhancer, e.g., R9 (SEQ.ID NO. 2) or R10 (SEQ. ID NO. 3). The solution comprises 0.001 .mu.M-100mM R9 (SEQ. ID NO. 2) or R10 (SEQ. ID NO. 3). Alternatively, acomposition of R9 or R10 is formulated into a solid suppository or a geland administered vaginally at dosages ranging between 0.001 mg to 10 gper application or day. The formulations may be admixed with additionaltherapeutic agents such as muscle-relaxers or painkillers.

Example 6

A patient diagnosed with glaucoma is treated with a NO enhancercomposition comprising, e.g., R9 or R10. The composition can beadministered topically or subcutaneously (e.g., via microinjections) tothe outer aspect of the trabecular meshwork or inner walls of theSchlemm's canal. The composition can be formulated as a solution,ointment or gel. The composition can further include any one or more ofthe following agents: pilocarpine, timolol maleate, betataxolol HCl,epinephrine, dipivefrin, demecarium bromide, echothiophate iodide,carbonic anydrase inhibitors, alkaloids, atrial natriuretic factorpeptides, substituted 2-aminotetralins, phenylimino-imidazoles,betaxolol salts, minoxidil, nitroglycerin, isosorbide dinitrate,nitroprusside, cyclic guanosine 3′,5′-monophosphate specificphosphodiesterase type 5 (cGMP-PDE5) inhibitor, A3 subtype adenosinereceptor antagonists, calmodulin antagonists, antiestrogens, potassiumchannel blockers, oncomodulin, a cAMP modulator, and15-keto-prostaglandin.

Example 7

A patient diagnosed with anal fissures may be treated with a NO enhancercomposition comprising, e.g., R9 or R10. The composition can beadministered topically or subcutaneously. The composition can furtherinclude anesthetics, painkillers, antibacterial, antifungal, andanti-inflammatories. The composition can be formulated into a gel, creamor a solution and administered rectally to the patient at dosages of0.001 mg to 10 g per day.

Example 8

A patient diagnosed with pulmonary arterial hypertension may be treatedwith a NO enhancer composition comprising, e.g., R9 (SEQ. ID NO. 2) orR10 (SEQ. ID NO. 3). The composition can be administered by inhalation.The NO enhancer is formulated as an aerosol solution and may furthercomprise an anesthetic, painkiller, antibacterial, antifungal,anti-inflammatory, and calcium channel blockers. The solution preferablyincludes 0.001 .mu.M-100 mM of the NO enhancer and is administered atregular intervals, e.g., hourly, daily, weekly, or as needed.

Example 9

A patient diagnosed with erectile dysfunction is treated with localadministration of a NO enhancer(s). The NO enhancer(s), e.g., R9 (SEQ.ID NO. 2) or R10 (SEQ. ID NO. 3), can be administered, for example,subcutaneously by microinjection or topically by applying a gel or asolution directly to the penis, the penile arterial blood vessel, and/orthe trabecular meshwork. The solution or composition to be administeredcomprises 0.001 .mu.M-100 mM or may be applied in dosages ranging from0.001 mg to 10 g per application. The compositions can also includeadditional therapeutic agents.

The above examples and description are provided only for the purpose ofillustrations and are not intended to limit the invention in any way. Aswill be appreciated by the skilled person, the invention can be carriedout in a great variety of ways, employing more than one technique fromthose described above, all without exceeding the scope of the invention.All of the references and publications disclosed herein are incorporatedby references in their entirety for all purposes.

1. A method for treating vulvodynia in a patient comprisingadministering locally to said patient a therapeutically effective amountof an arginine polymer comprising at least 8 consecutive arginineresidues.
 2. The method of claim 1 wherein said composition is anarginine homopolymer.
 3. The method of claim 2 wherein said argininehomopolymer consists essentially of L-arginine residues.
 4. The methodof claim 1 wherein said composition is administered subcutaneously,topically, or vaginally.
 5. The method of claim 3 wherein saidcomposition is administered topically.